SAN FRANCISCO -- – In case you've missed it, Silicon Valley has its own version of Occupy Wall Street.

This culture war lacks rampant arrests, bursts of violence or national media coverage, but the dissent of anti-gentrification groups over income and housing is creating a stir just the same here.

For the third time in about a month, protesters on Tuesday blocked tech buses from Google and Facebook carrying workers out of the city. A few dozen protesters, chanting "Stop evictions," surrounded the buses and prevented them from moving. Some plastered a sign to one of the coaches, in a Google-type font, that read "Gentrification and Eviction Technologies."

Demonstrators stood outside the Berkeley home of a Google engineer on Wednesday to object to the company's work on military robots.

San Francisco has always shown a predilection for protest. Hippies protested the Vietnam War. The gay community strove for civil rights. The Mission neighborhood resisted gentrification it blamed on tech start-ups in the early 2000s – though things weren't as heated then.

Members of the Housing Rights Committee of San Francisco and other activists protest outside of City Hall in San Francisco, Tuesday, Jan. 21, 2014. San Francisco officials are set to vote on a plan to start regulating employee shuttles for companies like Google, Facebook and Apple, charging a fee for those that use public bus stops and controlling where they load and unload. Private shuttle buses have created traffic problems, blocking public bus stops during peak commute hours.(Photo: Jeff Chiu AP)

For some, the buses that transport employees from Google, Apple, Facebook and others to Silicon Valley have become symbols of income disparity. The impact of its workforce is creating an eviction crisis," says Rebecca Gourevitch, an organizer with Eviction Free San Francisco. "A lot of people feel these companies make so much money, and … yet are oblivious."

The protests highlight the yawning gap between those benefiting from the enormous wealth generated by the tech boom and those left behind. Multimillion-dollar tax breaks to mollify SF-based companies like Twitter have only added to the angst.

The average monthly rent here has soared 12%, to $3,096, from a year ago, according to RealFacts. In San Jose, the average rental price is $2,124, up 10% from last year; in Oakland, the average rent climbed 9%, to $2,015.

Rent hikes have coincided with a migration of tech start-ups here, and the decision by many of their young employees to live in the city. The sweeping gentrification has not only altered the character of some neighborhoods, but alienated residents who complain of the self- entitled, boorish behavior of tech workers.

The imbroglio has long-time residents torn. "I see all sides," says Craig Phillips, 44, a 20-year city resident who's worked as a Google contractor, at nonprofits and for dot-com startups. "Tech companies do bring jobs, but many of the workers bring attitudes as well."

"A lot of tech workers come from elsewhere, and don't have some sort of anchor or sentiment for the city," he says. "I can understand the rebellion against tech hipsters."

Much is at stake -- with Twitter and Square recently moved into larger digs here – and some tech leaders appear to be getting the message. They've promised to create more jobs and affordable housing.

"We're working with Bay Area leaders to address the issue with practical response -- truly equipping people at the margins with the skills to participate in the new and emerging economy," says Mark Wexler, executive director of Not For Sale, an anti-human trafficking organization with the backing of several tech firms. He plans to meet with Jim Wunderman, CEO of the Bay Area Council, in two weeks to address economic disparity. Former Apple exec James Higa is assisting.

Salesforce.com CEO Marc Benioff, a fourth-generation San Franciscan whose name is imprinted on the UCSF Benioff Children's Hospital and has made Salesforce a model for corporate philanthropy, says he is "dismayed" by the industry's "stinginess."

"Companies are making billions of dollars; they can give back a small percentage of that back," says Benioff, who supports the rights of the protesters. "The homeless, child care and public schools are logical philanthropic targets for tech."

It was in San Francisco, not Silicon Valley, where Salesforce was founded in 1999. He says "200, not 20" local tech companies need to change their attitudes before things become more confrontational.

"This is a city of innovators – the Haas family (Levi Strauss), the Hellmans (Wells Fargo) who helped create industries" while being model corporate citizens, Benioff says.

"We need to create a new San Francisco, a better San Francisco," he says.